1. Field of the Invention
The present invention relates to β-SiAlON, a method of producing the β-SiAlON, a phosphor using the β-SiAlON, and a light-emitting apparatus using the phosphor.
2. Description of the Related Art
As a phosphor for light-emitting devices (LED), β-SiAlON phosphor is known. The β-SiAlON phosphor is produced by filling a vessel made of boron nitride with starting materials, namely a mixture of, silicon nitride, aluminum nitride, at least one compound selected from aluminum oxide and silicon oxide, and optically active element compound as typified by europium oxide and cerium oxide, and subjecting the materials to sintering process where sintering is performed at temperatures ranging from 1820° C. to 2200° C.
As a technique of improving luminescence intensity of β-SiAlON phosphor, subjecting sintered and crashed materials obtained by sintering process to acid treatment is known (Patent Literature 1).